May weather forecastBethalto, IL
May
Weather in May
The last month of the spring, May, is a warm month in Bethalto, Illinois, with an average temperature varying between 57°F (13.9°C) and 74.1°F (23.4°C).Temperature
In Bethalto, the average high-temperature in May rises, from a comfortable 64.4°F (18°C) in April, to a moderately hot 74.1°F (23.4°C). Throughout the May nights, Bethalto encounters a low-temperature of 57°F (13.9°C).Humidity
The average relative humidity in May in Bethalto is 79%.Rainfall
The month with the most rainfall in Bethalto, Illinois, is May, when the rain falls for 16.6 days and typically aggregates up to 3.07" (78mm) of precipitation.Snowfall
May through October are months without snowfall in Bethalto.Daylight
The average length of the day in May in Bethalto is 14h and 19min.On the first day of May, sunrise is at 6:01 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 5:36 am and sunset at 8:19 pm CDT.
Sunshine
The average sunshine in May in Bethalto is 9.3h.UV index
May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the average person.Note: In May, the maximum UV index of 6 suggests these recommendations:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Avoid direct Sun exposure and seek shade between 10 a.m. and 4 p.m., when UV radiation is at its peak, but keep in mind that not all shade structures provide complete protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Bethalto, IL
- Average high temperature in May: 74.1°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in May: 57°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in May
Bethalto, IL
- Average pressure in May: 29.95"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in May
Bethalto, IL
- Average wind speed in May: 7.6mph
The windiest months (with the highest average wind speed) are January and February (9.6mph).
The calmest month (with the lowest average wind speed) is July (5.7mph).
Average humidity in May
Bethalto, IL
- Average humidity in May: 79%
The month with the highest relative humidity is July (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in May
Bethalto, IL
- Average rainfall in May: 3.07"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is February (1.14").
Average rainfall days in May
Bethalto, IL
- Average rainfall days in May: 16.6 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is January (5.6 days).
Average snowfall in May
Bethalto, IL
- Average snowfall in May: 0"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Bethalto, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Bethalto, IL
- Average daylight in May: 14h and 18min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in May: 9h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 30min).
Average sunshine days in May
Bethalto, IL
- Average sunshine days in May: 12.5 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is July (12.3 days).
Average UV index in May
Bethalto, IL
- Average UV index in May: 6
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in May
Bethalto, IL
- Average cloud cover in May: 38
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June, July and August (Cloud cover 29).
Average visibility in May
Bethalto, IL
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





